Understanding the future of pharmacogenomics testing in patient care

Pharmacogenomics, often referred to as PGx, is a budding field of personalized medicine, and studies how genes influence an individual’s response to treatment with medications. To learn more and register for Washington State University’s new course on pharmacogenomics,  visit our continuing education platform in collaboration with the WSU Elson S. Floyd College of Medicine. The course begins Monday, February 27 and runs through Friday, May 12, 2023. Pharmacotherapy Associate Professor (Yakima) Rustin Crutchley shares how patients and care providers can use pharmacogenomics as an added tool in their arsenal of treatment options.

When should a patient ask their care provider about considering pharmacogenomic testing?

Today pharmacogenomic (PGx) testing is usually ordered reactively when a patient is experiencing troublesome side effects from medications or when medications are not working as well as expected. A patient should be encouraged to ask a provider about considering PGx testing in this type of clinical scenario, especially, since payer coverage is more likely in these type of settings (for example- treatment failure with medications used for treatment of depression and anxiety).

How common is PGx testing amongst health care providers now and what is the future of PGx being commonly used to treat patients?

Greater clinical uptake of PGx testing and consumerism is anticipated to grow exponentially in the future. Numerous institutions have implemented pharmacogenomic specialty clinics in both academic and community settings (reference: Teresa T. Ho et al. Am J Health-Syst Pharm. 2022;79:1634-1644). Some examples of these institutions include Brigham and Women’s Hospital (Boston, MA), Children’s Minnesota (Minneapolis, MN), Mission Health (Asheville, NC), NorthShore University Health System (Evanston, IL), and University of South Florida Health (Tampa, FL). These clinics follow a 2-visit model involving both pre- and post-test counseling visits. Goal of these consult services are to inform patients of the benefits, risks, and purpose of PGx testing as well as to provide adequate follow up patient counseling regarding results and how they can be used to guide and optimize medication management for various disease states. Although preemptive PGx testing (i.e. testing done prior to initiation of treatment) is infrequent, a very recent study from Europe demonstrated that using a 12-gene pharmacogenetic panel to initially guide treatment significantly reduced the incidence of clinically relevant adverse drug reactions (reference: Swen JJ et al. Lancet 2023; 401: 347–56). This study supports feasibility of this type of PGx testing across various European health-care system in real world settings. As costs of PGx testing become more affordable, movement to using preemptive PGx testing is inevitable as this one-time testing has clinical utility that can be used over a lifetime.

How does your PGx course help physicians and pharmacists care for their patients?

The Interprofessional Clinical Pharmacogenomics Certificate program is an interactive practice-based program designed to equip physicians and pharmacists with greater readiness, confidence, and advocacy for optimizing medication management using PGx data. This program provides physicians and pharmacists with the skill set in knowing how to use freely available PGx resources such as Clinical Pharmacogenetics Implementation Consortium (CPIC) and Pharmacogenomics Knowledge Base (PharmGKB) to guide clinical decision making for patients who have completed pharmacogenomic testing results. Furthermore, the interprofessional clinical pharmacogenomics certificate program covers important therapeutic areas such as cardiovascular disease, depression, pain, drug-induced hypersensitivity reactions and oncology, where PGx testing is most likely to be observed and used. Another important aspect of this program is providing patients with appropriate counseling regarding PGx data. This session as well as the others in the program are led by well-known experts in the field, giving participants one-on-one opportunities to engage in live discussion sessions so that they are best prepared for delivering excellent patient care.

If people want to do pharmacogenomics testing, what are tests you recommend?

Numerous vendors exist that offer PGx testing. It is best for individuals to ask their physician about this testing and how to go about getting this done. The genetic testing registry (GTR) is a very helpful resource developed by the National Institutes of Health intended primarily for health care providers and researchers. In addition, this site provides an information resource for the public, particularly health care providers, to locate laboratories that offer these particular tests. Additional information is also covered in the clinical of implementation session in the certificate program.

What do you teach PharmD students in your pharmacogenomics elective?

The Advances in Clinical Pharmacogenomics elective is offered to both second- and third-year pharmacy students at WSU College of Pharmacy and Pharmaceutical Sciences during the spring semester. This course builds upon the basic concepts and the knowledge-based aspects introduced during a required Basic and Clinical Pharmacogenomics course in the spring semester for first-year students. The elective course covers a broad range of new topics including gene-environmental interactions and application of knowledge of PGx to numerous different disease states such as hypersensitivity reactions, neurology, diabetes, transplantation, and infectious diseases as well as a much greater in-depth discussion of common disease states such as cardiology, pain management, mental health and oncology. This course concludes with discussion on entrepreneurial aspects of clinical implementation of PGx and medication management of a comprehensive patient case with polypharmacy. Students also have an optional opportunity to use their own raw genetic data from 23andMe using the Test2Learn platform. The Test2Learn platform allows students to use their own raw genetic data as the basis for making appropriate drug therapy recommendations for different patient case scenarios discussed in various disease state lessons throughout this course. Students choosing to opt out of personal genomic testing with 23andMe are also given an equal opportunity to work with actual genetic data available within the Test2Learn program by downloading anonymous datasets from the Harvard Personal Genome Project (HPGP) or 1000 Genomes. Student personal genomic testing is a unique pedagogical tool intended to increase engagement with the content of this course. Overall, this course prepares pharmacy students with a diverse knowledge of clinically relevant topics in PGx, serving as an excellent foundation for students interested in pursuing a future career in PGx. Furthermore, this course also prepares students for the precision medicine aspects of the HIV Precision Medicine APPE elective rotation offered annually during the summer in Cape Town, South Africa.